Asthma Exacerbation in Adults and Adolescents

Background

• Asthma exacerbation refers to an acute or subacute episode of increased asthma symptoms caused by decreases in expiratory airflow.
• Symptoms may include shortness of breath, cough, wheezing, and/or chest tightness.
• The most prominent triggers are respiratory tract infections, allergens, and air pollutants.

Evaluation

• Assess severity of exacerbation by clinical history, exam, and peak expiratory flow (PEF).

Table 1. Global Initiative for Asthma Exacerbation Severity Classification

• Chest x-ray and electrocardiogram are not recommended for routine assessment.

Management

General Treatment Measures

• Administer oxygen to most patients in the emergency room (ER) or hospital to maintain oxygen saturation (SaO₂) > 93%.
• Administer short-acting beta-2 agonist (SABA) (Strong recommendation).
• Add ipratropium to SABA in ER in patients with moderate-to-severe exacerbations or refractory exacerbations to reduce the rate of hospital admission (Strong recommendation).
• Guidelines recommend systemic corticosteroids for all exacerbations (unless very mild) to speed resolution of exacerbation and prevent relapse (Strong recommendation).
• Consider high-dose inhaled corticosteroids in the emergency department (Weak recommendation).
• Magnesium sulfate 2 g IV over 20 minutes may reduce hospital admission in adults with acute asthma.
• Routine use of antibiotics is not recommended for the management of asthma exacerbations unless the patient has signs or symptoms of a bacterial infection.

Table 2. Doses of Frequently Used Medications for Asthma Exacerbations

Emergency Room and Hospital Management

• For patients presenting to acute care/emergency departments:
  • If impending respiratory failure, do not delay intubation (Strong recommendation).
  • Consider careful assessment and monitoring with (Weak recommendation):
    • serial measurements of lung function (that is, forced expiratory volume in 1 second [FEV₁] or peak expiratory flow [PEF]); may be useful in assessing exacerbation severity
    • pulse oximetry and provide titrated oxygen therapy accordingly to maintain oxygen saturation at 93%-95%; oxygen should not be withheld if pulse oximetry is not available
    • arterial blood gas (ABG) depending upon the severity of the exacerbation
  • Signs and symptoms scores may be useful to help predict the need for hospitalization early in the course of emergency department treatment (Weak recommendation):
    • assessment scores combine clinician-observed severity of signs and functional assessment (if feasible)
    • presence of drowsiness is a useful predictor of impending respiratory failure
    • admit to hospital if pretreatment forced expiratory volume in 1 second (FEV₁) or peak expiratory flow (PEF) < 25% predicted, and consider admission if > 8 beta-2 agonist puffs needed in last 24 hours, features of severe exacerbation (such as respiratory rate > 22 breaths/minute), or history of severe exacerbations
  • Identification of the risk of respiratory failure and need for hospitalization includes assessing for:
    • incomplete response to treatment (indicating need for hospitalization), characterized by:
      • FEV₁ or PEF rate ≥ 50% but < 70% of predicted or personal best effort
      • continuing or slowly improving symptoms
    • poor response to treatment (indicating need for admission to intensive care unit), characterized by
      • FEV₁ or PEF rate < 50% of predicted or personal best effort
      • arterial carbon dioxide > 42 mm Hg
      • signs of patient fatigue (for example, confusion, obtundation)
  • Management in the emergency room and during hospital care is guided by severity of exacerbation and response to treatments.

Hospital or Emergency Room Discharge Care

• Patients should be provided with education (including inhaler technique), referral for follow-up appointment, and asthma discharge plan prior to discharge from emergency department or hospital (Weak recommendation).
• Short course of corticosteroids following emergency department discharge for asthma exacerbation may reduce the number of relapses and hospitalizations without apparent increase in side effects.
• Patients given systemic corticosteroids should continue oral systemic corticosteroids for 5-7 days (Strong recommendation).
• Consider starting inhaled steroid therapy at discharge (Weak recommendation).

Outpatient and Home Care

• For patients presenting for outpatient care, management depends on severity of exacerbation. Transfer to acute care facility if exacerbation is severe or worsens despite treatment; while transferring manage symptoms with short-acting beta-2 agonist, ipratropium bromide, oxygen, and systemic corticosteroid.
• Severity determines appropriateness of home management - immediate medical attention after initial treatment if:
  • high risk for fatal attack
  • PEF < 50% predicted or personal best
• General principles of home management:
  • Beginning treatment at home avoids treatment delays, can prevent exacerbations from becoming severe, and can increase patients' sense of control over asthma.
  • The degree of care provided in home depends on patients' (or parents') abilities and experience and on availability of emergency care.
• Home management in nonsevere exacerbations may include:
  • increasing frequency of short-acting beta-2 agonist (Strong recommendation)
  • increasing frequency of inhaled corticosteroid/formoterol combination (whether used as reliever or controller)